A second batch of Taliban and al-Qa'ida detainees were transported from Afghanistan to the US Naval Station at Guantanamo Bay on Cuba last night, in the face of mounting international criticism over the United States' handling of combatants captured. As with the first group of 20 detainees, who arrived at Guantanamo Bay on Friday, the 30 prisoners were hooded and many of them shackled as they walked under heavy military escort across the runway at Kandahar airport.

They are expected to be tried by military commission, rather than in a conventional court. They could be condemned to death without a jury and without right of appeal.

Criticism of the US has come from foreign and domestic observers, since the detainees will be treated as unlawful combatants, rather than as prisoners of war subject to the rules of the Geneva Conventions. Guantanamo Bay has traditionally been considered to be outside the jurisdiction of US federal courts.

This means that any decision made by the military will not be subject to judicial review of any kind.

Geoffrey Robertson QC, a prominent human rights lawyer, accused the US of skirting the rules of international law. He said the only fair way to treat the detainees would be to send them to an international tribunal like those set up after the Rwandan genocide and the Yugoslav wars of secession.

"The military commission is not a court at all. It is three paid and promoted officers who will decide whether individuals are executed without any clear indication of whether they have committed a crime," he said.

A spokesman for the International Committee for the Red Cross said: "We consider them to be prisoners of war. When you take prisoners from the battlefield you have to release them after the activities."

Donald Rumsfeld, the US Defence Secretary, said he intends to treat the prisoners in a manner "roughly" consistent with the Geneva Conventions. The Foreign Office said one prisoner at Guantanamo was a Briton.

The Australian Broadcasting Corporation televised segments of what it said was an amateur videotape showing al-Qa'ida militants rehearsing attacks on Western targets, including a mass assassination at a golf event .The tapes showed fighters rehearsing hostage-takings, using live ammunition, on a simulated motorcade on a mock-up American road.